Final answer:
The total mass number and atomic number of the parent particles in a nuclear reaction must equal the sum of the mass numbers and atomic numbers of the daughter particles and any other products, due to the conservation of mass and charge.
Step-by-step explanation:
In nuclear reactions, the total mass number of the parent particles must equal the sum of the mass numbers of the daughter particles and any other particles produced in the reaction. This is a consequence of the law of conservation of mass. Similarly, the atomic number of the parent must equal the sum of the atomic numbers of the products, reflecting the conservation of charge.
For example, in a nuclear reaction, if the mass numbers of the products total 254 (from, say, mass numbers of 118, 132, and 4), then the parent particle must also have a mass number of 254. As for the atomic numbers, if the daughter particles have atomic numbers that add up to 98, then the parent particle must have an atomic number of 98 as well.